Solar particle energy spectra

J. E. Mazur
	The Aerospace Corporation, El Segundo, CA 90245-4691

Solar particle energy spectra record the energetic particle production at impulsive flare sites and within events associated with traveling interplanetary shocks. The spectra constrain models of the acceleration process because they show the maximum energies that particles attain as well as the overall distribution of their energy. With the instrumentation on board ACE, we are able to measure the energy spectra of a wide range of elements from supra-thermal (~ 10s of keV/nucleon) to well above 10 MeV/nucleon with higher time resolution than previously possible. We will present examples of spectra measured at 1 AU with ACE, focusing on ions accelerated in impulsive solar flares. These particle events have unique elemental and isotopic enhancements, are solar in origin, and occasionally occur in isolation from other sources of solar or interplanetary energetic particles. We will emphasize the ACE measurements that show that propagation through the interplanetary medium has significant effects on the measured spectra at 1 AU.